stillwell



2 Sheets-Sheet 1.

(No Model.)

L. B. STILLWELL.

REGULATOR FOR SYSTEMS 0F ELEOTRIGAL DISTRIBUTION.

Patented Mar. 5, 1889.

Ait' yS Fig i (No Model.) 7 2 Sheets-S heet 2. L. B. STILLWELL REGULATOR FOR SYSTEMS 0P ELEGTRIGAL DISTRIBUTION. No. 399,218. Patented Mar. 5,1889.

7 1 Figa.

WITNESSES: INVENTOR,

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UNITED STATES PATENT @rrrcn.

LEXVTS ll. STILLXVELL, OF PITTSBURG, PEXXSYLYAXTA, ASSIGNOR TO THE \VEC'llXGHOl'SE ELECIRIC COMPANY, OF SAME PLACE.

REGULATOR FOR SYSTEMS OF ELECTRlCAL DiSTRiEUTiON.

SPECEFICELTEOIJ forming part of Letters Patent No. 399,218, dated March 5, 1889.

Application filed October 26, 1883- Serial No. 289,238- .No model- 1'0 a i/ whom it may con/0cm:

3e it known that I, LEWIS B. s'rILLwELL, a citizen of the United States, residing in Pitts burg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Regulators for Sys toms of Electrical Distribution, (Case No. 247,) of which the following is a specification.

The invention relates to those systems of electrical distribution in which alternating, intermittent, or pulsatory electric currents are employed for operating translating devices located at various more or less distant points. In organizing such systems it is customary to arrange the translating devices in groups dependent upon their locations and to supply the requisite currents to the different groups from a common source through independent supply circuits or feeders, as they are commonly termed. in practice it is found that the difference of potentialap plied to the translating devices through these feeders is liable to vary from time to time, even though the difference of potential applied thereto at the central station is maintained approximately constant. T he variations in the diiference of potential at the translating devices are usually due to the different resistances of the different supply circuits or feeders and to the varying work being done in the circuits. It is evident that if conductors of a given size are employed for each of the supply-circuits the resistances of those circuits will vary according to their lengths, so that if the same difference of potential is applied to all of the feeders at the source the difference of potential at the translating devices will be in some circuits greater than in others. If the amount of work being done in any given circuit is increased or decreased, the

current required in that circuit will beincreased or decreased accordingly, and there fore the loss of potential upon that circuit will be greater in proportion as the work is increased or less as the work is decreased. if the variations in the loss upon the several different feeders were coincident, then the difference of potential applied to the translating devices might be maintained approximately constant by increasing or diminishing the difference of potential applied at the station; butit is evident that if the loss upon one circuit increases while that upon another remains constant an increased difference of potential applied'to all the circuits would result in an undue increase of potential applied to the translating devices in those circuits requiring no change, so that it becomes necessary to provide means for varying the difference of potential applied to any given circuit without sensibly changing that applied to the others. In systems of distribution where secondary generators or converters are connected in the feeders and translating devices are connected in their secondary circuits there is a slight loss of potential in the converter itself, dependent upon the load or work being done in the secondary circuit.

The object, therefore, of my invention is to overcome these difficulties, and to provide means for obtaining any required difference of potential upon any given circuit and for compensating for the loss or drop in any given circuit, whether due to the resistance of the conductors conveying the current from the source to the translating devices or to the varying work being done, or to any other cause, and to insure that each group of translating devices shall at all times be supplied with a proper difference of potential.

Prior to my invention it has been proposed to construct the translating devices which are placed in the different groups so as to require a difference of potential dependent upon their distance from the source of supply or upon the loss in the feeding-circuits leading thereto. This plan is objectionable for the reason, among others, that it involves different forms of translating devices for different feeders and does not provide for the varying number of translating devices which are being operated and the consequent variation in the drop upon the line.

My invention consists in developing a normal electro-motive force at the central station sufficient to supply the requisite difference of potential to the translating devices included in the circuits having the least loss or drop, and in increasing the difference of potential upon any given circuit by ap 'ilying a supplemental electro-motive force to that circuit sufficient to compensate for the loss or drop, or to raise the difference of potential to any required extent that may be desired 5 for other reasons. It also involves the obtaining of any required variations in the amount of electro-motive force added to any circuit. This maybe accomplished in different ways, two of which will be described in IO connection with the accompanying drawings.

Instead of developing a difference of potential sufficient only to supply the translating devices in the circuits having the least drop,

however, it may be sometimes desirable to develop a higher electro-motive force and reduce the difference of potential upon certain circuits while increasing it upon others. Such a system'is described in another application of even date herewith filed by me.

In the drawings, Figure 1 represents one organization of circuit adapted to carry out the invention, and Fig. 2 is a modification.

Referring to the figures, G represents any suitable source of alternating, intermittent, z 5 or pulsatory electric currents, and L L a circuit derived therefrom. This circuit may be supplied either directly or indirectly from the generator or through an electric converter.

The regulator may be connected to the cir- 5o cuit at the central station or at a point at any distance therefrom, as required.

From the circuit L L different supply circuits or feeders, 1 2 and 3 4:, are derived.

These respectively supply groups of trans 55 lating devices, as shownat cl cl and (1 d? The devices may be supplied with current either directly from the conductors 1 2 and 3 1 or through electric converters, as shown at 0 C The translating devices may be elec- 4o tric lamps, electric converters, electric motors, or other electrically-operated apparatus.

Only one converter is shown as connected in the separate feeders; but any required number may be so connected. Considering now that the circuit 3 4: is longer or for some other reason has a greater drop or loss of potential than the circuit 1 2, then, unless means are provided to prevent it, there will be less difference of potential applied to the terminals of the primary coil 11 of the converter C and consequently the translating devices (1 will be supplied with a less difference of potential. For this reason, therefore, a device,

(7", is employed for adding to the difference of potential upon the circuitfiat an additional difference of potential sufficient to compensate for the drop or loss upon that circuit. This device consists, in the organization shown in Fig. 1, of an electric converter having its primary coil p connected between the lines L I), or across the respective poles of the source G, and its secondary coil 3 connected in the conductor 4.. The coils of the converter are so wound and connected with reference to each other that the current induced in the secondary coil will be in the same direction as that flowing through the conductor 4, so that the additional electromotive force applied to this conductor will assist in maintaining a required difference of potential at the terminals of the primary coil of the converter C For the purpose of regulating the amount of the additional electro-motive force thus obtained an adjustable selfinductive device or reactive coil, T, is connected in the primary circuit of the converteror regulator C. This has the effect of reducing to a greater or less extent the difference of potential applied to the primary coil 13 of the regulator, as may be required, for changing the added difference of potential. The parts are so organized that when all the translating devices (I are being operated the induced electro-mot-ive force thus obtained will approximately compensate for the loss or drop upon the line, so that an approximately-constant difference of potential will be maintained at the terminals of the primary coil p of the converter C As translating devices are cut out of circuit or the work being done is diminished, the loss upon the line will be decreased and also the loss in the converter.

By moving the core 15 of the selfinduction device T farther into the coils the difference of potential applied to the primary coils of the regulator C may be diminished, and consequently electro-n'lotive force developed in the secondary coils 8 maybe gradually reduced until the difference of potential at the terminals of the secondary coil of the converter C is reduced to the normal. In this way, by changing the reactive effect of the device T, the translating devices will be supplied with the proper difference of potential at all times.

In Fig. 2 a modification is illustrated in which the ratio of conversion of the converter may be adjusted by varying the length of one of the coilsthe secondary, for instanceby means of a switch, S, applied to switch-points .9, connected with different points in the length of that secondary coil. The ad j ustable reactive coil may be employed in connection with the adjustable converter, if desired. It is evident that two or more regulators, 0*, may be applied to any given feeder-circuit without departing "from the spirit of my invention.

\Vhere numerous different circuits of various lengths or losses are employed, a regulator of the character described may be applied to each of the circuits for the purpose of affording the required compensation.

In some instances it is desired to normally maintain a higher difference of potential upon one or more of the feeders than upon the others. This may be done in precisely the manner described with reference to compensating for the drop or loss. By varying the ratio of conversion the difference of potential applied to any given feeder may be increased as de sired.

In another application of even date here with the method of operation herein set forth is described and claimed.

I claim as my invention 1. The combination of a source of alternating intermittent or pulsatory electric currents, independent electric circuits derived therefrom, an electric converter having one coil connected in one of the derived circuits, and an independent circuit connected directly across the poles of said source and including only the second coil of the converter, whereby currents will be caused to traverse said second coil in value directly dependent upon the current traversing derived circuit, said coils being wound and connected so that the currents induced in the first-named coil are superposed upon those traversing said derived circuit, substantially as described.

The combination, with a source of alternating, intermittent, or pulsatory electric currents, of circuits derived therefrom, and an adjustable converter having one coil connected in one of the said derived circuits, and a spe cial independent circuit including the other coil connected in the circuit of said source in parallel with said derived circuit, the coils of said converter being so wound and connected as to superpose induced currents upon the current traversing said derived circuit.

natin g, intermittent, or pulsatory currents, of two or more groups of translating devices "respectively supplied with currents therefrom, and an electric converter having its secondary coil connected in the circuit supplying one of said groups and its primary coil connected in the circuit of the source of current independently of any other translating or transforming device, whereby an additional electro-motive force is applied to said circuit, and means for varying the amount of additional electromotive force thus applied.

th- The combination, wit-h a source of alter- 5 n ating, intermittent, or pulsatory electric currents, of two or more converters having their primary coils connected with said source in multiple are, and a variable number of translating devices connected in their respective secondary circuits, and a device for superposing electric currents upon the primary circuit of one of said converters, consisting of an electric converter having one ot its coils connected in said primary circuit in series with the converter included therein and its other coil connected in multiple are with said converter.

5. The combination, with a source of alternating, intermittent, or pulsatory electric currents, of two or more circuits receiving currents therefrom, a regulator for one or more of said circuits, consisting of an electric converter having one coil independently con nected in circuit with said source between points of approximately constant difference of potential and its other coil delivering currents to the circuit to be regulated, the firstnamed coil receiving currents opposite in direction from those traversing the last-named coil.

d. The combination, with a source of alternating, intermittent, or pulsatory electric currents, of two or more circuits receiving currents therefrom, a regulator for one or more of said circuits, consisting of an electric converter having its primary coil independently The combination, with asource of alterconnected in circuit with said source between points of approximately constant difference of potential and its secondary coil delivering currents to the circuit to be regulated, the said primary coil receiving currents opposite in direction from those traversing the secondary. circuit, and an adjustable reactive coil in series with the primary coil of said convert er.

In testimony whereof I have hereunto subscribed my name this 23d day of October, A.

\Vitnesses:

tjaannns A. 'lnnnv, (2 (J. ll'omn.

Lil 

